DESCRIPTION: Background: The workplace is a key site where individuals confront two types of health hazards. One is physical hazards, referring to such phenomena as dusts/fumes, static load, and noise. The other is social hazards, referring to such phenomena as job strain, racial discrimination, sexual harassment, and violence. Yet, to date, as acknowledged by leading researchers in the fields of occupational health and social epidemiology, remarkably little research explores the extent to which physical and social hazards are: (1) inter-related, (2) distributed among workers with respect to job type, race/ethnicity, and gender, and (3) synergistic in their adverse effects on health, broadly understood as both health behaviors (such as cigarette smoking) and health status (e.g., blood pressure). Specific Aims: The specific aims are to examine: (1) associations between hazardous physical exposures (dust/fumes, noise, ergonomic strain), hazardous social exposures (racial and gender discrimination, sexual harassment, violence, job strain), and socio-demographic characteristics (race/ethnicity, gender, and wage level); and (2) associations between hazardous physical exposures, hazardous social exposures, and health outcomes (health status, blood pressure, and health behaviors). Study design and methods: Cross-sectional survey on a racially and ethnically diverse population of male and female unionized workers engaged in a wide range occupations in the greater Boston area (n= 2,000). Outcomes: Our study addresses significant gaps in knowledge about social and physical hazards at work and their contributions to social inequalities in health. By selecting a well-justified set of determinants and outcomes, in combination with an appropriate study population, our study has the potential to expand public health knowledge about and efforts to reduce social inequalities in health.